455 research outputs found
Development of ductile cladding for TD-nickel turbine vane applications Final report, 5 Jul. 1967 - 31 Dec. 1968
Slurry technique for applying NI-CR-AL-SI coatings to TD-N
A Simple Model of Heat Distribution at Various Rayleigh Number in Silicon Elastomer
In order to investigate the two-dimensional flow of a non-Newtonian fluid, such as an elastomer liquid over a cylinder, a simplified model is applied. The analysis is carried out to study the thermophysical properties of the melt elastomer flow with Prandtl variable in the presence of internal heat generation. The temperature-dependent physical properties such as velocity, contour temperature, surface temperature as a function of contour velocity, and pressure are considered and discussed. Moreover, the exchange of energy from the surface to the fluids is examined through the variation in the Rayleigh number
An Efficient In Vitro Propagation Protocol of Cocoyam [Xanthosoma sagittifolium (L) Schott]
Sprouted corm sections of “South Dade” white cocoyam were potted and maintained in a greenhouse for 8 weeks. Shoot tips of 3–5 mm comprising the apical meristem with 4–6 leaf primordial, and approximately 0.5 mm of corm tissue at the base. These explants were treated to be used into the culture medium. A modified Gamborg's B5 mineral salts supplemented with 0.05 μM 1-naphthaleneacetic acid (NAA) were used throughout the study. Thidiazuron (TDZ) solution containing 0.01% dimethyl sulfoxide (DMSO) was used. Erlenmeyer flasks and test tubes were used for growing cultures. The effect of different media substrate, thidiazuron, and the interaction between TDZ and Benzylaminopurine (BAP) on cocoyam culture were tested. Results indicated that cocoyam can be successfully micropropagated in vitro through various procedures. All concentrations tested (5–20 μM BAP and 1–4 μM TDZ) produced more axillary shoots per shoot tip than the control without cytokinins. Greater proliferation rates were obtained through the use of 20 μM BAP and 2 μM TDZ, respectively, 12 weeks from initiation. Shoots produced with BAP were larger and more normal in appearance than those produced with TDZ, which were small, compressed, and stunted. The use of stationary liquid media is recommended for economic reasons
Sarcopenia and vitamin d deficiency in patients with crohn’s disease: Pathological conditions that should be linked together
Sarcopenia is a prevalent condition in patients with Crohn’s disease (CD), representing an independent predictor factor for the development of major postoperative complications. Thus, a proper assessment of the muscle strength, by using different validated tools, should be deemed an important step of the clinical management of these patients. Patients with CD are frequently malnourished, presenting a high prevalence of different macro-and micro-nutrient deficiencies, including that of vitamin D. The available published studies indicate that vitamin D is involved in the regulation of proliferation, differentiation, and regeneration of muscle cells. The relationship between vitamin D deficiency and sarcopenia has been extensively studied in other populations, with interesting evidence in regards to a potential role of vitamin D supplementation as a means to prevent and treat sarcopenia. The aim of this review was to find studies that linked together these pathological conditions
Liderazgo y creación social: una aproximación a las principales aportaciones
La conceptualización del liderazgo y la creación social son los ejes funda- mentales de este artículo. Partiendo de la relevancia del liderazgo en las ciencias socia- les, se realiza una revisión de literatura científica sobre liderazgo en empresas, política y movimientos sociales, y organizaciones escolares. Además, se incluyen el concepto de creación social y algunos de los elementos comunes con el liderazgo. La presentación de conceptos y los avances en estos ámbitos sugieren la necesidad de seguir investigando sobre las dinámicas de cambio implícitas en estos conceptos.
The conceptualization of leadership and social creation are the fundamental topics explored in this article. The relevance of leadership in the social sciences is the point of departure from which we undertake a review of the scientific literature on leadership in companies, political and social movements, and school organizations. We also include a discussion of the concept of social creation and some of the elements it shares in common with leadership. The presentation of concepts and the advances in these areas suggest the need to continue investigating the dynamics of change implicit in these concepts
An index based road feature extraction from LANDSAT-8 OLI images
Road feature extraction from the remote sensing images is an arduous task and has a significant role in various applications of urban planning, updating the maps, traffic management, etc. In this paper, a new band combination (B652) to form a road index (RI) from OLI multispectral bands based on the spectral reflectance of asphalt, is presented for road feature extraction. The B652 is converted to road index by normalization. The morphological operators (top-hat or bottom-hat) uses on RI to enhance the roads. To sharpen the edges and for better discrimination of features, shock square filter (SSF), is proposed. Then, an iterative adaptive threshold (IAT) based online search with variational min-max and Markov random fields (MRF) model are used on the SSF image to segment the roads and non-roads. The roads are extracting by using the rules based on the connected component analysis. IAT and MRF model segmentation methods prove the proposed index (RI) able to extract road features productively. The proposed methodology is a combination of saturation based adaptive thresholding and morphology (SATM), and saturation based MRF (SMRF), applied to OLI images of several urban cities of India, producing the satisfactory results. The experimental results with the quantitative analysis presented in the paper
Endemicity response timelines for Plasmodium falciparum elimination
Background: The scaling up of malaria control and renewed calls for malaria eradication have raised interest in defining timelines for changes in malaria endemicity. Methods: The epidemiological theory for the decline in the Plasmodium falciparum parasite rate (PfPR, the prevalence of infection) following intervention was critically reviewed and where necessary extended to consider superinfection, heterogenous biting, and aging infections. Timelines for malaria control and elimination under different levels of intervention were then established using a wide range of candidate mathematical models. Analysis focused on the timelines from baseline to 1% and from 1% through the final stages of elimination. Results: The Ross-Macdonald model, which ignores superinfection, was used for planning during the Global Malaria Eradication Programme (GMEP). In models that consider superinfection, PfPR takes two to three years longer to reach 1% starting from a hyperendemic baseline, consistent with one of the few large-scale malaria control trials conducted in an African population with hyperendemic malaria. The time to elimination depends fundamentally upon the extent to which malaria transmission is interrupted and the size of the human population modelled. When the PfPR drops below 1%, almost all models predict similar and proportional declines in PfPR in consecutive years from 1% through to elimination and that the waiting time to reduce PfPR from 10% to 1% and from 1% to 0.1% are approximately equal, but the decay rate can increase over time if infections senesce. Conclusion: The theory described herein provides simple "rules of thumb" and likely time horizons for the impact of interventions for control and elimination. Starting from a hyperendemic baseline, the GMEP planning timelines, which were based on the Ross-Macdonald model with completely interrupted transmission, were inappropriate for setting endemicity timelines and they represent the most optimistic scenario for places with lower endemicity. Basic timelines from PfPR of 1% through elimination depend on population size and low-level transmission. These models provide a theoretical basis that can be further tailored to specific control and elimination scenarios
Modeling the Compressibility Behavior of Hard Red Wheat Varieties
Citation: Turner A., M. Montross, S.G. McNeill, M.P. Sama, M.E. Casada, J.M. Boac, R. Bhadra, R.G. Maghirang, and S.A. Thompson. Modeling the compressibility behavior of hard red wheat varieties. 2016. Transaction of ASABE 59(3): 1029-10385.The bulk density of grain in a storage structure varies vertically and horizontally due to the overburden pressure created by the cumulative weight of the overlying material. As the overburden pressure increases, the stored material compacts. This compaction is believed to be caused by rearrangement of kernels along with higher intergranular stress between particles, leading to kernel deformation. This compaction is of primary concern when estimating the amount of grain in a storage structure. In this comprehensive study, confined uniaxial compression tests were conducted on 27 different samples of hard red winter wheat, at three moisture levels, over the range of pressures typically encountered in storage structures (0 to 138 kPa). Mathematical models using the prior, modified, and new forms of the bulk density equation were evaluated to describe the resulting pressure-density relationship as a function of moisture content. With the new data set, the modified version of the Page equation had the lowest root mean square error (RMSE) of 4.7 kg m-3, while the other equations, including the original polynomial equation used in the WPACKING program, had RMSEs between 6.0 and 7.1 kg m-3. The models were validated using previously published compressibility data and the root mean square prediction error was determined to vary from 8.1 to 13.4 kg m-3. Four of the best performing models were subsequently applied to field measurements from 35 concrete and 16 steel bins. When applied to the field data a slight bias was observed in steel and concrete bins, but several of the models, including the modified Page and polynomial models, produced an average error of less than 2% from the measured grain mass
Energy Performance of Advanced Reboiled and Flash Stripper Configurations for CO2 Capture Using Monoethanolamine
CO2 capture by absorption using amine solvents has the potential to significantly reduce the CO2 emissions from fossil-fuel power plants. One of the major costs of this technology is the energy required for solvent regeneration. Complex process configurations claim to have promising potential to reduce the energy required for solvent regeneration. In this work, the effect of flow-sheet complexity is explored by studying two advanced stripping flow sheets: an advanced flash stripper and an advanced reboiled stripper. Both advanced configurations recover the stripping steam heat by means of a heat integration comprised of cold- and warm-rich solvent bypasses. The advanced configurations are simulated and optimized in Aspen Plus V.8.4 using 7 m monoethanolamine (MEA) with lean loading from 0.15 to 0.38 (mol CO2/mol MEA). The rich loading associated with each lean loading is determined by simulating the absorber providing 90% capture from flue gas with 4 mol % CO2, typical of a natural gas-fired turbine. The results are compared to a simple stripper in terms of total equivalent work. Both the advanced reboiled stripper and the advanced flash stripper require 12% less equivalent work than a simple stripper. The associated cold-rich and warm-rich bypasses for the optimum cases are, respectively, 20% and 50% for the advanced reboiled stripper and 15% and 35% for the advanced flash stripper
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